Agricultural sprayer and method

ABSTRACT

A system for agricultural spraying including a solution reservoir and primary pump for delivering fluid to a plurality of laterally spaced nozzles interconnected by supply conduits. A chemical reservoir and chemical injection pump are interconnected to the output of the primary pump through a mixer. Controllers for the primary pump and chemical injection pump are coordinated to run the pumps a predetermined time to fill each of the supply conduits from the chemical injection pump and primary pump so as to automatically prime the injection system.

FIELD OF THE INVENTION

The present invention relates to sprayers, and, more specifically, to sprayers of liquid for agricultural purposes, including chemical additives.

BACKGROUND OF THE INVENTION

Currently, there are numerous systems for adding chemical to a preexisting solution system, which, in turn, is sprayed by a mobile sprayer over an agricultural field. The chemical addition and the solution are selected for particular application of herbicides, insecticides, and the like. With all such systems, it is important to precisely control the amount of solution and chemical only to those sections of the field desired. For this purpose, it is necessary, in existing systems, to manually prime the system. As used herein, the term “prime” does not necessarily refer to the operation of supplying liquid to the inlet of a pump so that it pumps liquid and not air or a mixture of air and liquid. It primarily refers to filling the lines from the respective pumps to the mixer and/or nozzles carried by the agricultural spraying unit.

In current systems, operators rely on experience with the system and/or visual coloring of the chemical to determine when the system is fully primed. When the chemical has no color, the operator must rely on a gut feeling and past experience to operate the pump for a long enough time to prime the line. In addition, the solution lines from the solution pump to the nozzles must be primed and this adds further uncertainty to the system. The uncertainty associated with this procedure creates the potential for wasted chemical, carrier fluid, wasted time, or inefficient application of chemical in the field due to incomplete system priming.

Accordingly, what is needed in the art is a system that automatically primes the conduits so as to enable efficient spraying.

SUMMARY

In one aspect of the invention, a system is provided spraying liquid for agricultural purposes including an at least one liquid reservoir, a plurality of laterally spaced nozzles, and segmented supply conduits extending between the supply reservoir and the nozzles. A pump is provided for delivering liquid from the reservoir at a preselected volume rate to the plurality of nozzles. A controller is provided for the pump to operate the pump for a predetermined time dependent upon the internal volume of the segmented supply conduits and the preselected volume flow rate to fill and prime the supply conduits.

In another form, the invention is a method for spraying liquid for agricultural purposes with a system delivering the liquid through supply conduits to multiple laterally spaced nozzles from a central location. The method includes the steps of selectively segmenting the supply conduits to the spaced nozzles. The internal volume of the segmented supply conduits is determined. The application volume rate of the liquid is determined. The time to fill the segmented supply conduits at the application volume rate is calculated and liquid is delivered through the segmented supply conduits substantially for the calculated time so that the segmented supply conduits are full and primed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows in schematic fashion a system for spraying liquid for agricultural purposes, and

FIG. 2 illustrates the steps used in practicing the present invention.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one embodiment of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

DETAILED DESCRIPTION

Referring now to the drawings, and more particularly to FIG. 1, there is shown in schematic form an agricultural spraying system 10. Only the fluid handling details of agricultural spraying system 10 will be discussed to simplify the understanding of the present invention. However, typical agricultural spraying systems have propulsion systems and other components enabling travel through a field. The system may be mounted on or towed by another vehicle, such as a tractor, or may be a self-propelled unit.

In either case, the system has a plurality of nozzle sets 12, 14, and 16 laterally spaced relative to the direction of motion through a field so as to treat multiple rows. As shown herein, the nozzles in nozzle sets 12, 14, and 16 each have a check valve that permits flow above a preselected level. Although only three sets of nozzles 12, 14, and 16 have been shown, it should be apparent to those skilled in the art that many more sets may be employed depending upon the width of the treatment area. The nozzles 12, 14, and 16 receive a liquid solution from a reservoir 18 for application in the field. The solution may be a fertilizer or other component suspended in an aqueous solution. Whatever the properties, the solution passes through an outlet conduit 20 to the inlet of a primary, or solution, pump 22. Solution pump 22 may be appropriately driven by a rotary power source (not shown) to pressurize fluid for delivery through an outlet conduit 24 past a flow meter 26 to a mixing section 28. From there, the solution passes through conduit 30, including a pressure sensor 31 to branch conduits 32, 34, and 36, each terminating at control valves 38, 40, and 42 respectively. Valves 38, 40, and 42 are respectively connected to conduits 44, 46, and 48 leading to the respective nozzle sets 12, 14, and 16.

As illustrated, the spraying system 10 mixes a chemical with the solution flow and, for this purpose, a chemical reservoir 50 is provided and has an outlet conduit 52 in which a strainer 54 is interposed and connects with the inlet of a chemical injection pump 56, herein illustrated as a positive displacement pump so that flow is directly proportional to pump rpm. The output from chemical injection pump 56 passes through conduit 58 past an injection system valve 60 and through a conduit 62 to the mixer 28. A conduit 64 provides a recirculation flow of chemical back to reservoir 50 from valve 60.

In typical fashion, the reservoir 50 is provided with chemical from a shuttle tank 66 feeding an outlet conduit 68 by gravity to a chemical transfer pump 70, which delivers chemical through an outlet conduit 72 to a control valve 74, passing chemical into the bottom of reservoir 50 through conduit 76. Valve 74 functions as a fill and drain valve as appropriate by a suitable control function.

In addition, the chemical reservoir 50 is provided with a rinse function from a rinse solution reservoir 78 feeding an outlet conduit 80 through a rinse pump 82 delivering rinse fluid to conduit 84, which, in turn, passes to the multifunction valve 74 controlling the rinse/drain/fill function and ultimately to conduit 86 providing rinse fluid to the top of reservoir 50. Details of this operation are not discussed in order to simplify the understanding of the present invention.

A controller 88 is provided for controlling the operation of valves 38, 40, and 42 through control interconnections 90, 92, and 94 respectively. Thus, the valves 38, 40, and 42 are opened or closed as necessary to provide spray through the various nozzle sets 12, 14, and 16. The controller 88 also controls the operation of the primary pump 22 through line 96. Primary pump 22 is typically a centrifugal pump requiring a variation in rpm to achieve a given volume flow rate. For this purpose, controller 88 receives signal inputs from the flow meter 26 via line 98 to vary the rpm and thus the volume flow rate. The pressure sensor 31, via line 100 provides an indication to the operator of the system operating pressure.

The chemical injection pump is controlled by a similar controller 102 via line 104 to provide appropriate operations and flow rates as-needed.

Heretofore, agricultural spraying systems have required manual priming, which carries with it the uncertainty and variation that have been discussed above. In accordance with the present invention, the controllers 88 and 102 are coordinated in such a way that the priming operation is automated. For this purpose, an interconnection between the controller 102 and 88 is provided by a control line 106 to a bus 108 and through to controller 88 via control line 109. A signal line 112 extends from the bus 108 to an operator control and display unit 110. An interconnection between the controllers enables sequential operation as described below.

The method of operating the system for automatic priming includes segmenting and determining the internal volume of conduits 58 and 62, which are associated with the chemical injection pump 56. In addition, the conduits 24, flow passages within mixer 28, conduits 30, and conduits 32, 34, 36, 44, 46, and 48 are segmented and the internal volumes of them are also determined. Coupled with the determined flow rate of both the injection pump 56 and the solution pump 24, a time to fill the respective conduits is determined, enabling a calculation of the time it takes to fully fill and prime the respective conduits.

The method is illustrated in FIG. 2 in which step 114 constitutes segmenting the supply conduits, in other words, segmenting conduits 58, 24, 30, 32, 36, 34, 44, 46, and 48. In step 116, the internal volume of each segmented supply conduit is determined. In step 118, the liquid application volume rate for the respective pumps is determined and, in step 120, the time period to fill each segmented supply conduit based on the volume and volume flow rate is calculated. In step 122, liquid is delivered through each segmented supply conduit for substantially the calculated time so that, in step 124, each supply conduit is full and primed.

In the normal operation of the spray system 10, the chemical injection pump 56 is operated for a period of time that takes into account the internal volume of conduits 68 and 62 and the flow rate through pump 56. When the time period has elapsed, the controller 102 terminates operation of the pump 56. At this point, the primary pump 22 is operated for the period of time calculated to fill conduit 24, internal passages, mixer 28, and conduit 30 to fill that conduit. As is apparent from FIG. 1, conduits 32 and 34 have a greater internal volume because of their length relative to that of the central conduits 36 and 46. Accordingly, the primary pump 22 is operated for the given period of time to fill all of the segmented conduits. However, the valve 40 is terminated when the calculated time means that conduits 36 and 46 are full. The primary pump 22 continues to operate for an additional period of time to fill conduits 32, 44 and 34,48, at which point the valves 38 and 42 close after the respective conduits are fully full of liquid. At this point, a signal is generated at the operator input and feedback device 110 to say that the system is fully primed and operational. At this point, the operator controls the application rate by coordinating the flow of the respective pumps 22 and 56 and the valves 38, 40, and 42. It should be noted that, because of the coordination between controllers 88 and 102, the system can be fully automated so that the operator may individually prime the circuits or do so in an automated sequence. It should be noted that the present invention, while illustrated with a chemical injection pump, may be employed in a system having only a solution reservoir and a primary pump. In that case, the same principles apply and the sequential termination of flow through valves 38, 40, and 42 may be employed.

The advantage of the above system is that it enables a fully automated priming operation with a minimum of spillage on the ground. This also reduces the amount of liquid used to prime because it is a calculated valve instead of one based on gut feel or experience. In addition, the sequential closing of the valves supplying the nozzle arrays minimizes the amount of liquid that is used for the priming and, accordingly, minimizes the time it takes to prime the unit. Spraying systems typically require flushing of the system to the nozzles with water so that while the segmented supply conduits may be full, they still need to be primed with the selected solution and chemical.

While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. 

1. A system for spraying liquid for agricultural purposes comprising: at least one liquid reservoir; a plurality of laterally spaced nozzles; segmented supply conduits extending between said supply reservoir and said nozzles; a primary pump for delivering said liquid from said reservoir at a preselected volume rate to said plurality of said nozzles; and a controller for said primary pump, said controller operating said primary pump for a predetermined time dependent upon the internal volume of said segmented supply conduits and said preselected volume flow rate to fill and prime said segmented supply conduits.
 2. The system of claim 1, further comprising a series of valves interposed in said supply conduits to segment said supply conduits, said controller operating said primary pump for given periods of time to fill each of said segmented supply conduits.
 3. The system of claim 2, wherein the segmented supply conduits closer to said primary pump are filled over a shorter time interval than said nozzles remote from said primary pump.
 4. The system of claim 1, further comprising a chemical injection pump; a supply conduit leading from said chemical injection pump; a mixer receiving flow from said primary pump and mixing it with the flow from said chemical injection pump; and, a controller for selectively operating said chemical injection pump to fill said chemical injection supply conduit prior to the filling of said segmented supply conduits for priming the entire system.
 5. The system of claim 4, wherein said chemical injection pump is a positive displacement pump.
 6. The system of claim 5, further comprising a chemical reservoir for chemical and connected to said chemical injection pump.
 7. The system of claim 6, further comprising a rinse pump connected to a supply of rinse liquid, the controller for said chemical injection pump also controlling said rinse pump to rinse said chemical supply reservoir.
 8. The system of claim 1, further comprising a flow meter measuring the flow from said first pump, the output from said flow meter being used to control the rate if operation of said primary pump.
 9. The system of claim 8, further comprising a pressure sensor sensing the pressure in the supply conduit from said first pump and providing said pressure signal to said controller.
 10. A method for spraying liquid for agricultural purposes with a system delivering the liquid through supply conduits to multiple laterally spaced nozzles from a central location, said method comprising the steps of: segmenting the supply conduits to said spaced nozzles; determining the internal volume of said segmented supply conduits; determining the application volume flow rate of said liquid; calculating the time to fill said segmented supply conduits at said application volume flow rate; and delivering liquid through said segmented supply conduits substantially for said calculated time whereby said segmented supply conduits are full and primed.
 11. The method of claim 10, wherein said liquid is delivered for a time to fill each segmented supply conduit.
 12. The method of claim 11, wherein the supply conduits closer to said central location are filled in less time than the conduits away from said central location.
 13. The method of claim 11, further including the injection of chemicals to said liquid through a mixer adjacent said central location for supply of liquid and injected chemical to said spaced nozzles and wherein the method further comprises: determining the internal volume of said chemical injection supply conduit to the mixer; determining the application volume rate of said chemical; calculating the time to fill said chemical injection supply conduit at said application flow rate; and delivering liquid through said chemical injection supply conduit substantially for said calculated time whereby said chemical injection supply conduit is full and primed.
 14. The method of claim 13, wherein said chemical is delivered through said chemical supply conduit prior to delivering liquid to said supply conduits, whereby the entire system is primed.
 15. The method of claim 14, wherein said liquid is delivered to fill said supply conduits closer to said central location than the supply conduits remote from said central location.
 16. The method of claim 13, wherein a primary pump is controlled by a controller and a chemical injection pump is controlled by a separate controller and wherein the method further comprises the step of interconnecting said controllers, whereby the delivering of liquid and chemical is coordinated, with the chemical injection pump priming its associated supply conduits before the primary pump primes its associated supply conduits. 